﻿// Copyright 2008 Chris Varley (http://www.contractdriven.net/)
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//    http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

namespace ContractDriven.CommonAssertions
{
	/// <summary>
	/// Describes a guarantee that a string is neither null, nor empty.
	/// </summary>
	public class EmptyStringAssertion : IAssertion
	{
		private readonly string _target;
		
		/// <summary>
		/// Describes a guarantee that a string is neither null, nor empty.
		/// </summary>
		/// <param name="target">the actual string to be checked.</param>
		public EmptyStringAssertion(string target)
		{
			Contract.Require(Assert.IsNotNull(target));
			_target = target;

		}		

        #region IAssertion Members

        public string FailureDescription
        {
            get { return Resource.EmptyStringAssertion; }
        }

        public bool Eval()
        {
            return !string.IsNullOrEmpty(_target);
        }

        #endregion
    }
}
